Early prediction of urinary retention following radical hysterectomy by 18F-FDG PET/CT imaging

BACKGROUND: Radical hysterectomy for early cervical cancer is associated with postoperative bladder dysfunction. Postoperative imaging by 18F-FDG PET/CT scanning is often performed to rule out recurrence. Since women are in-structed to empty the bladder before imaging, we aim to study if scanned abnormal residual bladder volume is associated with future urinary symptoms.METHODS: Women who underwent radical hysterectomy for cervical cancer between July 2010 and January 2019 were included in the study. Multi-Modality Tumor Tracking (R) (MMTT) was used to measure residual urinary volume on 18F-FDG PET/CT scans before and after hysterectomy. Demographic, clinical parameters, and urinary tract signs and symptoms, were evaluated among the cohort.RESULTS: Overall, 64 patients were included. Among those, in 24 (38%) the bladder volume reached >150 cm3 on postoperative 18F-FDG PET/CT scans. Of these, 9 (37.5%) had voiding difficulties of some degree. In 3 (12.5%) women, the 18F-FDG PET/CT scan has preceded their complaints of voiding difficulties by 2-4 months. Of the 40 women (62%) whose postoperative bladder volumes were <150 cm3, only 1 (2.5%) had urinary retention. Rate of symptomatic voiding difficulties was higher in the post-void volume >150 cm3 group; 13 (54.1%) vs. 6 (15.0%), P<0.002, Odds Ratio 95% Confidence Interval 6.6 (2.0-21.8), P=0.001.CONCLUSIONS: Measuring bladder volume on postoperative 18F-FDG PET/CT may facilitate early identification of urinary retention, possibly enabling early treatment and possibly preventing complications.